import java.util.ArrayList;
import java.util.List;

public class Node {
private List<Node> children = new ArrayList<Node>();
private Node parent = null;
private Node data = null;

public Node(Node data) {
    this.data = data;
}

public Node(Node data, Node parent) {
    this.data = data;
    this.parent = parent;
}

public List<Node> getChildren() {
    return children;
}

public void setParent(Node parent) {
    this.parent = parent;
}

public void addChild(Node data) {
    Node child = new Node(data);
    child.setParent(this);
    this.children.add(child);
}


public void removeParent() {
    this.parent = null;
}
}